Magnet-tester.



R. T. CARLSON. MAGNET TESTER.

APPLICATION man FEB-19,1917- 1 260,869. Patented Mar. 26, 1918.

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MAGNET-TESTER.

S eciiicatiOn of Letters Patent.

Patented Mar. as, rare.

Application filed matey 19, 1917. Serial'No. 149,660.

To all whom it may concern:

.Be it known that I, RICHARD T. Gnnnson, a citizen of the United States, residingat Rosedale, in the county of VJyandotte and State of Kansas, have invented certain new and useful Improvements in Magnet-Test ers, of which the following is a specification.

My invention relates to testing instruments for measuring the potential energy of electromagnets, permanent magnets, and other electrical devices, and while said instrument is adapted for general use, it is intended .more particularly for testing the electrical equipment of automobiles.

In order that the invention may be fully understood, reference will now be had to the accompanying drawings, in which:

Figure 1 is a side elevation ofthe instrument. i

Fig. 2 is a plan view of the instrument.

Fig. 3 is an irregular longitudinal sectional view on line III-J11 of Fig. 1, with a bridge plate constituting a portion of the invention, removed.

Fig. 4: is 'a perspective view of the auxiliary bridging bar.

4 designates a plunger reciprocably mounted in the handle 1 and having its forward end extending outwardly through an opening in the cap 2 and provided with a cross bar 5, rigidly secured thereto.

6 designates a coil springloosely-embracing the plunger 4 and having one end abutting the cap 2 and its opposite end abutting a washer 7 held upon the rear threaded end of said plunger 4 by a nut 8, whereby the tension on the spring 6 may be regulated.

10 designates a detent adapted to engage ratchet teeth 11 on the plunger 4 to hold the same outwardly. against the action of the The detent 10 has two oppositely-disposed trunnionsl l pivotally-mounted in a bracket 15 secured upon the handle 1 adjacent the cap 2. A small spring 16 is interposed between the handle 1 and the rear end of the detent 10, to normally hold the front end thereof in engagement with an underlying tooth 11. V

18 designates a finger hold secured to the underside of the handle 1 near its forward end to afford a grip for the forefinger when pulling the instrument away from an electrical device beingtested.

19 designates a bridge plate removably secured to the cross bar 5, to bridge two poles of a magnet, or other electrical device, when said poles are fspacedtoo far apart to be bridged by the cross bar 5. The cross bar 5 and the bridge plate 19 are made ofsoft steel or other suitable magnetic substance,

"ferably, consists of agood quality of steel such as is used in scales and other measuring instruments. 7

A scale 21 is formed on the handle 1, be side the teeth 11, to coact with the detent 10 in determining the attractive force of an electrical device being tested.

In practice, the plunger 4 is initially adjusted backwardly in the handle 1 until the cross bar 5 contacts the front side of the detent 10. The cross bar 5, or the bridge plate 19, as the case may be, is then applied to the electrical device to be tested, after which the handle 1 is pulled backwardly by hand against the action of the spring 6, thereby compressing the same until the magnetic force of the electrical device is overcome and the cross bar 5, or the bridge plate 19, is pulled away from said device. After the instrument has been pulled out of contact with the electrical device the potential energy of the latter is readily determined by the scale 21 and the detent 10, which engages with the underlying ratchet tooth 11 and prevents the spring 6 from forcing the plunger 1 backwardly until said detent 10 is manually raised out of engagement with ,Said ratchet tooth.

From the foregoing description it is apparent that I have produced a testing instrument whereby the magnetic potential energy of electrical devices can be quickly and accurately measured, and while I have shown and described the preferred form of my invention I reserve the right to make such changes in the construction, combination, and arrangement of parts as properly fall within the spirit and scope of the claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

1. In a magnet tester, a tubular handle, a spring tensioned plunger in the handle having teeth and graduations, a bar extendmg transversely of the plunger and secured at its longitudinal center to the outer end of the plunger, a bridging plate removably secured. to the outer side face of the bar, a.

its longitudinal center to the outer end of the plunger, abridging plate removably se- 15 curedto the outer side face of the bar, a finger piece depending from the handle, and a spring pressed detent carried by the handle and engaging the teeth of the plunger.

In testimony whereof I affix my signature 20 in the presence of two Witnesses.

V RICHARD T. CARLSON. Witnesses:

GUsTAF A. HAGSTROM, F. G. FISCHER.

fioples of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. G. 

